First Author | Pfrengle F | Year | 2013 |
Journal | J Immunol | Volume | 191 |
Issue | 4 | Pages | 1724-31 |
PubMed ID | 23836061 | Mgi Jnum | J:205703 |
Mgi Id | MGI:5546274 | Doi | 10.4049/jimmunol.1300921 |
Citation | Pfrengle F, et al. (2013) Copresentation of antigen and ligands of Siglec-G induces B cell tolerance independent of CD22. J Immunol 191(4):1724-31 |
abstractText | Differentiation of self from nonself is indispensable for maintaining B cell tolerance in peripheral tissues. CD22 and Siglec-G (sialic acid-binding Ig-like lectin G) are two inhibitory coreceptors of the BCR that are implicated in maintenance of tolerance to self Ags. Enforced ligation of CD22 and the BCR by a nanoparticle displaying both Ag and CD22 ligands induces a tolerogenic circuit resulting in apoptosis of the Ag-reactive B cell. Whether Siglec-G also has this property has not been investigated in large part owing to the lack of a selective Siglec-G ligand. In this article, we report the development of a selective high-affinity ligand for Siglec-G and its application as a chemical tool to investigate the tolerogenic potential of Siglec-G. We find that liposomal nanoparticles decorated with Ag and Siglec-G ligand inhibit BCR signaling in both B1 and B2 B cells compared with liposomes displaying Ag alone. Not only is inhibition of B cell activation observed by ligating the BCR with Siglec-G, but robust tolerance toward T-independent and T-dependent Ags is also induced in mice. The ability of Siglec-G to inhibit B cell activation equally in both B1 and B2 subsets is consistent with our observation that Siglec-G is expressed at a relatively constant level throughout numerous B cell subsets. These results suggest that Siglec-G may contribute to maintenance of B cell tolerance toward self Ags in various B cell compartments. |